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  • Allergic asthma  (3)
  • Phenylephrine  (3)
  • Blood cells  (2)
  • 3-dimethylindole  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Tetrahedron Letters 35 (1994), S. 6063-6066 
    ISSN: 0040-4039
    Keywords: 2 ; 2 ; 2 ; 3-dimethylbenzofurans ; 3-dimethylindenes ; 3-dimethylindole ; Dimethyldioxirane ; deoxygenation ; dioxetanes ; epoxides ; phosphine ; phospholanes ; quinone methides ; singlet oxygen
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 67 (1989), S. 799-803 
    ISSN: 1432-1440
    Keywords: Cystic Fibrosis ; Blood cells ; Beta-adrenoceptors ; Cyclic AMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Several in vivo and in vitro studies have suggested that children suffering from cystic fibrosis (CF) might have a general defect of beta-adrenoceptors on the cell surface which might account for an unbalanced secretory process. In order to investigate if this view holds true, we determined the beta-adrenoceptor density and affinity on lymphocytes by means of radioligand studies using 125-iodo-cyano-pindolol (125-ICYP) in 20 children with CF. Cyclic AMP (cAMP) response was also investigated after specific beta-adrenoceptor stimulation with isoprenaline (IPN) and after direct stimulation of the adenylate cyclase with forskolin in lymphocytes. Children with CF and controls have identical numbers and affinities of beta-adrenoceptors on lymphocytes. The cyclic AMP response was identical in CF- and in age-matched control children regardless whether adenylate cyclase was stimulated directly or via beta-adrenoceptors. In conclusion, the data support the view that no general adrenoceptor or adenylate cyclase defect exists in CF. As several studies have found abnormal reactions to adrenergic stimuli in CF patients, we presume that there is a defect beyond the level of adrenergic receptors and cAMP which remains to be identified.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1440
    Keywords: Exercise induced asthma ; Allergic asthma ; Histamine ; Catecholamines ; Theophylline ; Plasma levels ; Anstrengungsasthma ; allergisch-bedingtes Asthma ; Histamin ; Katecholamine ; Theophyllin ; Plasmaspiegel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um zu untersuchen, ob endogene Transmitter bei der Auslösung und Unterhaltung verschiedener Formen des Asthma bronchiale eine Rolle spielen, haben wir bei Kindern vor und nach einer Laufbelastung sowie vor und nach einer inhalativen Provokation mit wäßrigen Allergenextrakten das Serumhistamin, Serumnoradrenalin und den bronchialen Strömungswiderstand (Rt) bestimmt. Die Untersuchung zeigt, daß das Belastungsasthma mit einem starken Anstieg des Plasmanoradrenalins, nicht jedoch des Plasmahistamins einhergeht. Dieser Anstieg war wesentlich ausgeprägter als der bei einem asthmatischen Vergleichskollektiv ohne Anstrengungsasthma. Im Gegensatz dazu zeigten die Kinder, die nach einer Allergenprovokation einen Asthmaanfall entwickelten, einen signifikanten Histamin-, jedoch keinen Noradrenalinanstieg. Zwischen Histamin-Serumspiegel und Stärke der Bronchokonstriktion bestand eine gute Korrelation (r=0.98). Nach oraler Applikation übte Theophyllin einen Schutz sowohl gegenüber dem Anstrengungsasthma, als auch gegenüber dem allergisch bedingten Asthma aus. Da Theophyllin beim allergisch ausgelösten Asthma nicht nur zu einem Abfall von Rt führte, sondern auch den Histaminanstieg verminderte, kann vermutet werden, daß ein Teil der Wirkung dieser Substanz beim allergischen Asthma auf einer Hemmung der Histaminfreisetzung beruht. Die Noradrenalinfreisetzung beim Anstrengungsasthma beeinflußte es nicht. Für seine protektive Wirkung bei dieser Asthmaform müssen daher andere Wirkungsmechanismen angenommen werden. Ob diese ausschließlich auf einer Relaxation beruhen, muß ungeklärt bleiben. Als Schlußfolgerung dieser Untersuchung wird deutlich, daß das Anstrengungsasthma und das allergische Asthma 2 verschiedene Typen eines Syndroms sind. Arzneimittel, die gegenüber beiden Typen wirksam sind, können dies über verschiedene Wirkungsmechanismen tun.
    Notes: Summary To investigate whether endogenous transmitters play a role in different forms of bronchial asthma we determined histamine and noradrenaline plasma levels as well as airway resistance (Rt) before and after exercise and allergen challenge in children. The study demonstrates that in exercise induced asthma (EIA) broncho-constriction was paralleled by increases of noradrenaline, but not of histamine plasma levels. This increase of noradrenaline was much more pronounced than that observed in the asthmatic control group not suffering from EIA. In contrast to what has been observed in EIA, bronchoconstriction in response to allergen challenge was closely associated with increases of histamine, but not of noradrenaline plasma levels. Between histamine concentrations and severity of illness a good correlation was found (r=0.98). Tests carried out after oral administration of theophylline showed a protection against EIAand allergic induced asthma. Since theophylline in allergic asthma concomitantly reduced the increase in Rt and plasma histamine it is suggested that at least part of the beneficial effects of theophylline in allergic asthma may result from inhibition of histamine release. In those children suffering from EIA theophylline did not affect noradrenaline release. Thus, consideration must be given to effects of theophylline against EIA which are based on other mechanisms. Whether these effects are solely attributable to relaxation of bronchial smooth muscle or not remains to be clarified. In conclusion this study clearly has identified exercise and allergic induced asthma as different types of the syndrome that we call asthma. Drugs which prevent against both types may do this by different modes of action.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1912
    Keywords: Atrium ; Guinea Pig ; Rabbit ; Cardiostimulation ; Phenylephrine ; β-Adrenoceptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experiments were performed on isolated electrically driven and spontaneously beating atria from guinea pigs and rabbits in order to characterize the cardiostimulatory effect of phenylephrine as either β- or α-sympathomimetic. 1. In electrically driven left atria (1 and 2 Hz) of guinea pigs the positive inotropic effect of phenylephrine was competitively antagonized by the β-adrenolytic drug pindolol but not by the α-adrenolytic agent phentolamine. The same was true for electrically driven (2 Hz) atria of rabbits. The intrinsic activity for phenylephrine amounted to only 0.3 in the guinea-pig atrium and 0.46 in the rabbit atrium. Also in preparations from reserpine-pretreated guinea pigs the positive inotropic effect of phenylephrine was blocked by pindolol and remained uninfluenced by phentolamine. Pretreatment with reserpine did not change the intrinsic activity of phenylephrine. Three other α-sympathomimetic drugs, oxymetazoline methoxamine and naphazoline did not cause any positive inotropic effect. 2. In spontaneously beating atria of either guinea pigs or rabbits the positive chronotropic effect of phenylephrine was competitively inhibited by pindolol. Phentolamine proved to be without any effect. The intrinsic activity for the positive chronotropic effect with 0.52 in guinea-pig atria and 0.47 in rabbit atria was less than that of isoprenaline (1.0). 3. The results presented here show that at least on atria only β-adrenoceptors are of functional importance.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 134 (1980), S. 45-50 
    ISSN: 1432-1076
    Keywords: Exercise induced asthma (EIA) ; Catecholamines ; Cyclic AMP ; a-Adrenergic blockade ; Allergic asthma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to provoke exercise induced asthma (EIA) a test which involved running for 7 min was performed with 21 asthmatic children. Eleven children not only developed a highly significant increase in airway resistance (Rt), but showed also a 4-fold increase in plasma noradrenaline (NA) levels. In 10 children who did not develop EIA only a 1.5-fold increase of NA could be observed. Following exercise cyclic AMP showed an identical increase in both groups studied, whereas adrenaline levels remained uninfluenced. Tests carried out after administration of phentolamine by inhalation showed a significant inhibition of post-exercise bronchoconstriction. It is concluded that EIA originates from a-receptor stimulation which is mediated by excessive noradrenaline release. However, since disodium cromoglycate—which does not act via adrenergic mechanisms—also protected against EIA, other factors should be involved. In 5 children with allergic asthma, asthmatic attacks were accompanied by a significant decrease in cAMP, whereas noradrenaline levels remained uninfluenced. Thus, evidence appears that both types of asthma result from different autonomic dysfunctions.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1076
    Keywords: Allergic asthma ; Children ; Phospholipids ; Fatty acids ; Glucocorticoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fatty acid (FA) composition of plasma phospholipids and phospholipids extracted from peripheral mononuclear white blood cells (MNC) was investigated in 11 allergic asthmatic children (age 8.9±4.6 years), in 10 age-matched non-allergic healthy controls and in 14 allergic and non-allergic children with an acute attack of asthma, who had received prednisolone medication for 2–4 days. In allergic asthmatics eicosapentaenoic acid (20∶5n−3) was significantly elevated in both plasma and MNC. The relative amount of 20∶5n−3 in MNC as well as in plasma correlated positively with increasing levels of total serum IgE (P〈0.02). The pattern of the other FAs in plasma and of MNC phospholipids did not differ between allergic asthmatic and non-allergic control children. In children with an acute attack of asthma, who had been treated with glucocorticoids (2 mg prednisolone/kg body weight for 2–4 days), distinct changes of relative FA composition of phospholipids were restricted to plasma, where some very long chain FA (22∶4n−6, 22∶5n−6) were elevated. No significant changes in FA from MNC phospholipids could be observed after glucocorticoid treatment. These findings may indicate a possible role of 20∶5n−3, the precursor of “group 3” eicosanoids, in allergic asthmatic children.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1076
    Keywords: Bronchial asthama ; Adrenergic theory ; α- and β-adrenoceptors ; Blood cells ; Age-dependent maturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Among the possible mechanisms which may cause wheezing or asthmatic episodes a genetically determined β-adrenoceptor blockade and a hyperresponsiveness of α-andrenoceptors has been postulated. Evidence to support this hypothesis stems from an increased bronchial sensitivity to β-blockers, a reduced formation of cyclic AMP in response to β-adrenergic stimulation and enhanced α-adrenergic responses in asthmatic subjects. The recent development of techniques for measuring the specific, high-affinity binding of radiolabeled α-and β-adrenergic antagonists made it possible to study α- and β-adrenoceptors in vitro. Based upon the assumption that a change in the number and/or affinity of adrenergic receptors might be a general phenomenon, we have performed α- and β-receptor binding studies on lymphocytes and platelets from wheezing infants and asthmatic children as well as of infants, children, and adults not suffering from these diseases. Using 125[I]-cyanopindolol (ICYP) and 3[H]-yohimbine (HYOH) as highly specific ligands for α- and β-adrenoceptors, the following results were obtained: (1) Lymphocytes and platelets from control subjects and asthamatics bound similar amounts of ICYP and HYOH and thus showed no differences either in the number or the affinity of α- and β-adrenoceptors. Lymphocytes and platelets of wheezing and nonwheezing infants also bound the same amounts of the radioligands. (2) In asthmatic children receiving 4×2 puffs salbutamol β-adrenoceptor were down-regulated and this may mimic β-adrenoceptor blockade. (3) When subjects were divided into four categories according to age (0–5, 5–10, 10–20 years, adults) the number of β-adrenoceptor binding sites showed an age-dependent increase. The number and affinity of α-adreneceptor binding sites on platelets was neither influenced by age nor disease. It is concluded that the α- and β-adrenoceptors of wheezing infants and asthmatic children at least on blood cells are normal. However the β-adrenoceptors show an age-dependent maturation process, which may account for an unresponsiveness to β-adrenoceptor agonists in wheezing infants.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 282 (1974), S. 307-310 
    ISSN: 1432-1912
    Keywords: Isolated Perfused Rabbit Heart ; Phenylephrine ; dp/dt max ; Heart Rate ; Adrenolytic Drugs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the isolated perfused rabbit heart the effect of phenylephrine on the left ventricular dp/dt max and on heart rate was investigated. 1. The positive inotropic effect of phenylephrine 3×10−7 to 3×10−6 M was abolished by the α-adrenolytic drug phentolamine (3×10−6 M), whereas the β-adrenolytic drug pindolol (10−8 M) was ineffective. On the other hand, the positive inotropic effect evoked by higher concentrations (10−5 to 10−4 M) of phenylephrine was blocked by pindolol while phentolamine was without any effect. 2. The positive chronotropic effect of phenylephrine was antagonized by pindolol. Phentolamine was ineffective. 3. The results presented here show that the ventricular myocardium of the rabbit contains both β- and α-adrenoceptors responsible for the mediation of the positive inotropic effect of phenylephrine.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 284 (1974), S. 245-261 
    ISSN: 1432-1912
    Keywords: Phenylephrine ; Isolated Organs ; Competitive Dualism in Action ; Local Anaesthesia ; Antiarrhythmic Activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The β-sympathomimetic effect of phenylephrine was investigated on the electrically driven atrium, as well as on the tracheal chain of the guinea pig. 1. Phenylephrine (PE) was found to be less effective than isoprenaline (IPN) with regard to its positive inotropic effect on the guinea-pig atrium and to its relaxing action on the tracheal chain. The intrinsic activity for PE amounted to 0.75 on the tracheal chain and to 0.45 on the atrium, when compared with IPN. 2. From these low intrinsic activities, PE was assumed to be a partial β-agonist, exerting a competitive dualism in action to IPN. This dualism could be confirmed by dose-response curves for PE in the presence of IPN and vice versa: PE behaved as a β-agonist as well as a β-antagonist. 3. The intrinsic activity of PE steadily decreased with prolongation of the incubation period. After 1 h PE had almost lost its intrinsic activity. Under these conditions the dose-response curves for IPN on the tracheal chain, as well as on atrium, were shifted to the right in a parallel manner, i.e. PE behaved as a competitive β-antagonist. 4. High concentrations of PE (10−3 M) protected the electrically driven guineapig atrium against arrhythmias induced by k-strophanthoside. The onset of both the first extrasystoles and of heart standstill, which occurred after infusion of k-strophanthoside, were delayed after preincubation with PE. 5. Phentolamine was without any influence on these antiarrhythmic properties of PE. Therefore, it could be excluded that the antiarrhythmic effect of phenylephrine is due to a stimulation of myocardial α-adrenoceptors. 6. The local anaesthetic activity of phenylephrine, as tested on the rabbit cornea, was 4 times higher than that of propranolol. 7. The effective concentrations for the β-adrenolytic, antiarrhythmic, and local anaesthetic activities of PE were clearly different. We concluded, therefore, that the different actions produced by phenylephrine were not associated with each other.
    Type of Medium: Electronic Resource
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